Stringed musical instrument



A. J. OSTRANDER. STRINGE'D MUSICAL INSTRUMENT. mwucmou FILEDJAN-26.1918. RENEWED FEB. 11, I921. 1,388,880.

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M E .H W m u 8M A. JLOSTRA'NDER.

STRINGED MUSICAL INSTRUMENT. APPLICATION FILED JAN.26, 19m. RENEWED FEB.11. um.

1,388,880. P n e A g.30,1921.

2 sums-sum 2. FIIE. 2. 3 48 UNITED STATES PATENT orrlca.

ALEXANDER J'. OSTBANDER, OF LYONS, NEW YORK.

STRINGED MUSICAL INSTRUMENT.

I Specification of Letters Patent.

Patented Aug. 30, 1921.

Application filed January 26, 1918, Serial No. 213,992. Renewed February17, 1921. Serial No. 445,851.

To all whom it may concern Be it known that I, ALEXANDER J. Os- TRANDER,a citizen of the United States, and resident of Lyons, in the county ofWayne and State of New York, have invented certain new and usefulImprovements in Stringed Musical Instruments, of which the following isa specification.

The present invention relates to stringed musical instruments, and anobject thereof is to provide for automatically maintaining a given pitchin each and every string of such instrument so that the periodic tuningby a piano tuner is rendered unnecessary. Another object of theinvention is to provide an instrument having means for maintaining aconstant or invariable tension in a string under any change in the totallength of such string due to changes in temperature, combined with meansfor mounting the string so that the effective length of the vibratingportion of the string is maintained constant during the changes in thetotal length of the string, without producing any friction on the stringdue to drawing the latter over a bridge piece. A further object is toprovide a movable bridge piece which will. maintain the vibrating lengthof a string constant notwithstanding adjustment of the string tomaintain a desired tension. Still another object of the invention is toprovide a common source of energy which will automatically maintain thepitch of a plurality of strings, preferably all of the strings of theinstrument, this common source of energy preferably being so connectedto the individual strings that the pitch of any one string may bechanged with relation to the others, the connections preferably alsobeing so constructed that, regardless of the initial tension ondifferent strings, a definite per cent. of increase or decrease intension may be obtained through the variation of the amount of energy.

To these and other ends the invention con sists of certain parts andcombinations of parts,'all of which will be hereinafter de scribed, thenovel features being pointed out in the appended claims.

In the drawings I Figure 1 is a cross-section of a part of a pianoshowing the method of stringing the instrument and the mechanism formaintaining a given degree of tension in the vibrating portions of thestrings;

Fig. 2 is a horizontal section onthe line 22, Fig. 1;

- 1Fig. 3 is a detail view of the channel p ate; 4

Fig. i is a detail view, showing the relative positionsof three of thestring levers;

Fig. 5 is a detail view of one of the blocks serving as fulcrums for astring lever;

Fig. 6 is a detail view of a modification of dthe manner of supportingthe strings; an

Fig. 7 is a sectional view through another embodiment of the invention.

The invention is herein shown as embodied in a pianoforte, but it willbe understood that it is not limited to instruments of this type but maybe embodied in other stringed musical instruments.

Referring more particularly to the embodiment shown in the drawings, 1,2 and 8 indicate three wires of a triple unison, these wires beingsecured in any suitable manner at their lower ends and having theirupper ends secured to pins 4: mounted in a manner to be hereinafter morefully described. Below the pins t the wires or strings are engagedeither by a'single bridge piece 5 common to the three wires, asshown inFig; 4, or separate bridge pieces 5 for each of the wires 1, 2 and 3, asshown in Fig. 6.

These bridge pieces are of novel construc tion and are mounted onfulcrums or axes 6, permitting said bridge pieces to swing in thedirection of the length of the strings or wires, these fulcrums being inthe form of knife-edge bearings resting against the bridge support 7 0nthe wrest plank 8. The bridge pieces 5 have curved faces 9 which areconcentric with the. axes 6 and bear against one side of the strings orwires to define thelength of the vibrating 0r effective-portions of thestrings or wires.

Also bearing against the strings or wires are clamp pieces 10 havingknife edges 11 resting against theclamp support 12, these clamp piecesalso being mounted to turn about the knife edges 11 as axes, and havingcurved faces l8 for engagement by the strings or wires, the curved facesbeing concentric with the axes 11. These clamp pieces tend to hold thestrings or wires firmly in contact with the curved faces 9 of the bridgepieces 5. It is apparent that any tension or pull on the upper ends ofthe wires 1, 2 and 3, in the direction of their lengths, will tendtorock the bridge pieces 5 and the clamp pieces about their respectiveaxes 6 and 11, without producing any friction on the wires. At the sametime, owing to the curvature 9 of the bridge pieces 10 and to therocking of the bridge pieces about fixed axes, the effective lengths ofthe vibrating portions of the wires or strings are not changed butremain constant or invariable, notwithstanding any adjustment of thestrings to maintain desired tension.

Another feature of this invention is a mechanism for producing tensionin a plurality of strings of a musical instrument of the type mentioned,said mechanism having a common source of energy and being so connectedto the difierent strings that the proper tension is applied to eachstring for maintaining a given pitch in such string, notwithstanding theeffects produced on the instrument due to changes in temperature. Thecommon source of energy which may be any suitable force, in thisinstance embodies a weight 14: suspended by a rod 15 which at its upperend is pivoted at 16 to a lever 17, in turn pivoted at 18 to a channelplate 19, the function of which will be hereinafter described. Thisweight or common source of energy acts upon a movable member or plunger20 of a fluid pressure chamber.

The fluid pressure chamber, in addition to the movable member orplunger, comprises a cylinder 21 held to a supporting head 22 by bolts23 with an interposed packing 22, and also a diaphragm-of tubularformation clamped at one end 24: between the cylinder and the head 22,cooperating with the interior walls of the cylinder, and provided with afold 25, the end 26 of the tubular diaphragm being secured to theplunger 20 beyond said fold. Vith the plunger 20 a pin pointbearing 27on the lever 17 is engaged so that the force'in the weight 14 iscommunicated to the piston or plunger 20. and through the latte and thediaphragm to a fluid within the chamber of the cylinder 21. From thiscylinder 21 a conductor tube 28 leads to the channel plate 19hereinbefore mentioned. This channel plate extends substantiallythroughout the length of the piano and has a longitudinally extendingchannel 29 to which laterals 30 are connected, each lateral 30 alsohaving branches 31 on opposite sides thereof. The channel plate 19 issecured to the rear face of a supporting member 32 which carries aplurality of pressure operated devices. Any suitable fluid may be usedfor transmitting power from the pressure chamber to the pressureoperated devices. The embodiment shown in Figs. 1 to 6, inclusive,employs mercury. I also may use Vaseline or a fluid preparation similarto that employed for rendering bicycle tires air tight.

Each pressure-operated device comprises,

in this instance, a cylinder and a plunger or piston 8-1, the pistonhaving a tubular diaphragm secured at one end at to the piston andprovided with a told 36, said diaphragm cooperating with the interiorwall of the open-ended cylinder 33 and being folded at 3'? about theinner end of the cylinder, the portion 3? lying between the outer wallof the cylinder and a screw-threaded bore in a support 32 so as to forma tight joint between the cylinder and such support 32. The inner end ofthe cylinder lies directly over one of the branches 31, so that pressurewithin the pressure chamber or cylinder 33 is communicated to each ofthe pistons 34L.

Connection between each piston or pressure-operated device 8 1- and thestring which it controls may be effected by providing the piston 34 witha knife-edge bearing 38 which cooperates with a lever 39 near the freeend of the latter. This lever 39 has a knife bearing 10 which restsagainst the fulcrum rail 41, the lever being engaged in proximity to itsfulcrum 4.0 by a shackle 42 to which a tie rod or connector 43 issecured. This tie rod has its other end secured to a shackle 44adustably mounted on a lever 45 on which the stringsecuring pin 4 ismounted. The lever has a knife edge 46 which rests upon a shoulder 17formed on the fulcrum block i8, this fulcrum block, in this instance,having three or such shoulders 47 arranged one above another so that itmay act as a support for the three levers 15 of a triple unison. Theshackles 42 and 44, being adjustably secured to their respective levers39 and 15, make it possible to vary the amount of tension applied to thevibrating string without changing the amount of pressure directlyexerted by the piston 34, so that should it be necessary to change thepitch of any one string, this can be effected by shifting the shacklesand 441 connected to said string. As soon as the proper pitch issecured, the shackles are secured in their adjusted position by theclamping screws 4-9, and the pitch of the string is dependent entirelyon the amount of pressure within the pressure chamber.

In the embodiment shown in Fig. 7, the support 32 for the pressureoperated devices is tormedwith bores 33" which act as the pressurechambers for the pressure opcrater devices. The tubular diaphragm ofeach pressure operated device has one end 37 secured at one end to thebe e, while the other end 35 issecured to the plunger 34. On the back ofthe support 32 a pressure chamber 28 is formed, this chamber having thebores 33 opening thereto. Through the top wall of the chamber 28 atubular member 21 i fitted, this tubular member having a beveled lowerend and containing a plunger 20 to which one end of the tubulardiaphragm 25 is connected, thediaphragm 25 being constructed similar toother diaphragms in this case. The upper end of the plunger 26 isengaged by a pin bearing 27 on a lever 17 which, by the rod 15, connectswith a suitable weight. lVhen the fluid matter is viscous, such asVaseline, the action of such Vaseline will be slow, so in connectionwith the fluid pressure chamber there is employed a yielding diaphragm50 in proximity to the lower beveled end of the tube 21, in order thatthe pressure in said tube will be directed immediately against said walland the latter will yield. This wall 50 is also common to an air chamber51 or chamber for some fluid such as air which is more active than thefluid in the chamber 28. As the air chamber 51 and the wall 50 extendthroughout the length of the pressure chamber 28, the air will re-actquickly throughout the length of the chamber, thus rendering thecommunication of a variation in pressure substantially instantaneous.The air chamber 51 may be provided with an air valve 52 through whichthe desired pressure of air in the chamber 51 may be introduced.

In operation, the pressure chamber and the connections are filled with asuitable fluid, the weight being adjusted to produce a suitable pressurein the pressure chamber. Each string is individually adjusted andpitched by turning the pin 4 and shifting the rod 43 on its levers 39and 45. Different degrees of tension required are secured approximatelyby giving greater or less cross sectional areas to the various pistons.When all the strings have been properly tuned or pitched the weight 14;through the. pressure operated devices will hold the pitchnotwithstanding any effects due to expansion and contraction underchanges in temperature. To raise the pitch of the entire instrument, theweight 1e may be increased, or to lower the pitch the weight may bedecreased.

From the foregoing it will be seen that there has been provided animproved manner of supporting the wires or strings of musicalinstruments. Both the length and the tension of the vibrating portion ofa string is rendered constant or invariable notwithstanding theexpansion or contraction of the total length of the string due tochanges in temperature. All of the wires or strings are controlled froma common source of power preferably through fluid .as distinguished frommechanical connections. The action of the weight on the pressure chamberis constant and the pressure chamber has fluid connections withpressureoperated devices acting on the'strings. Be-

7 tween the pressure operated devices and the strings are arrangedmechanical connections whlch may be so ad usted that any desired tensionon a string may be secured, that is,

the action of the pressure device on any string may be increased ordecreased to sesame increase or decrease in tension on the variousstrings but instead the same per cent. of variation in tension will beobtained, thus making it possible to raise or lower the pitch of theinstrument as a whole merely by increasing or decreasing the weight.

What I claim as my invention and desire to secure by Letters Patentis 1. A stringed musical instrument comprising a plurality ofdifferently tensioned strings and interrelated connections between thestrings for maintaining them under tension, said connections havingprovision for changing the tension of all of the strings simultaneouslya like per cent.

2. In a stringed musical instrument, a plurality of differentlytensioned strings, and interrelated connections between the stringshaving fluid means therein for maintaining the strings under propertension.

, 3. In a stringed musical instrument, a plurality of differentlytensioned strings, interrelated connections between the strings havingfluid means therein for maintaining the strings under tension, and meansfor main taining a desired pressure in said fluid means. 1. In astringed musical instrument, a plurality of differently tensionedstrings, and interrelated connections between all of such strings havingautomatically operating means for maintaining a given necessary degreeof tension on each string for the correct pitch of the string withrelation to the other strings.

5. In a stringed musical instrument, aplurality of differently tensionedstrings, and interrelated connections between all of such strings, saidconnections having automatically operating means for maintaining a.

given necessary degree of tension on each string for the correct pitchof the string, with relation to the other strings and said connectionshaving means adjustable to vary the pitch of the different strings withrelation to each other.

6. In a stringed musical instrument, a plurality of differentlytensioned strings and interrelated connections between all of suchstrings having fluid means therein, and means associated with saidconnections and adjustable to vary the pitch of any string with relationto the others.

7. In a stringed musical instrument, a plurality of differentlytensioned strings, and interrelated connections between the strings formaintaining the strings under tension too comprising a common fluidpressure chamber, means for Varying the pressure therein, 2L pluralityof fluid operated devices con nectcd With said chamber, one for each ofsaid strings, and adjustable mechanical operated devices between saidfluid connections and the strings.

8. In a stringed musical instrument, a plurality of differentlytensioned strings, and interrelated connections between the stringsembodyinga plurality of fluid operated devices and fluid connectionsbetween said devices.

ALEXANDER J. OSTRANDER.

